SharePoint - Need help in infopath form and sharepoint 2013 approval workflow.

Hi,
I am working on sharepoint 2013 out of the box approval workflow.While I am clicking on "Approve" button the "Outcome" field of "Tasks" list is updated as "Approved" but while I am clicking on "Reject" button the "Outcome" field of "Tasks" list is not updating which I am expecting to be updated as "Rejected".

I have set the Task Outcomes as below in SP Designer Task Form:

Sequnce Name Task Form
1 Approved Approve
2 Rejected Reject

Any help would be much appreciated.